Fish are known to be attracted and repelled by light. This fact has been used to advantage in a number of devices for either attracting or repelling fish and thereby guiding their movements.
For example, International published application Serial No. WO/25450 (Baugher et al.) discloses a strobe light system with underwater flash heads for repelling and directing the movements of migrating fish away from turbine intakes and other danger points at dams, hydroelectric facilities, and water intakes in lakes and rivers. In order to deliver light of the appropriate intensity and wavelength, xenon tube flash heads are preferably employed by this system. Although xenon tube flash heads are durable and efficient, they generate large amounts of heat. In order to prevent premature failure due to excessive heat buildup, the Baugher et al. system employs a complex heat monitoring and dissipation system including temperature sensors, internal cooling fans and air circulation means, which adds to the complexity and cost of the system. Clearly, it would be advantageous to provide an underwater fish repelling or attracting system which does not generate large amounts of heat.
Light is also used to attract fish in the commercial fishing industry. In commercial fishing operations, illuminating devices are commonly attached to fishing nets in order to attract fish. One such device comprises a tubular, water-tight container which is easily attached to a net and contains two chemicals in chambers separated by a breakable barrier. When the barrier is disrupted, the chemicals react with one another to produce a phosphorescent light source. One such device, commonly referred to as a "glowstick", is sold by Lindgren-Pitman, Inc. under the trademark Duralumes. While this system is much simpler and inexpensive than the strobe light system discussed above, the disadvantage exists that these devices are not reusable, and the intensity of the light given off by these devices declines in intensity after only a few hours. This is a considerable disadvantage in some commercial fishing operations, such as gill net fishing, where a net may be left at sea for several days before being retrieved. After the light given off by the glowsticks subsides, the net may be left without an effective light source for a number of days before it is retrieved.
Therefore, prior art fish attracting and repulsion systems suffer from numerous disadvantages which have not yet been overcome.